The present invention relates to apparatuses and methods for capsules used in coffee-making making machines and, more particularly to such capsules for espresso designed for optimal extraction rate and usable in a diverse variety of group heads.
In the process of coffee preparation using a coffee-making machine, one step in the process is utilization of a capsule containing coffee granules. The coffee granules in the capsule are subjected to a flow of heated water. As the water flows through the capsule, it is hoped that the water is evenly distributed throughout the capsule. Furthermore, according to coffee baristas, there is an optimal extraction rate for espresso. Achieving the ideal extraction rate is an art. It has been found to be in the ballpark of 0.20, which means about a 20% solubility rate of the solute, namely the granules, in the solvent, namely the water.
There are two ways to make espresso. The first is to use a professional barista who, like a bartender, artfully mixes the ingredients over a relatively long amount of time to create the ideal espresso using a professional espresso-making machine. This is an art. The second way is to use an espresso-making machine that utilizes a coffee capsule. The advantage of making the espresso with a coffee capsule is that it is easier, cleaner and more standardized. The cost of the barista is also saved. The drawbacks include the fact that this method does not achieve as high a quality of espresso, whether measured by taste, flow or other subjective criteria. This outcome may be because when using the coffee capsule to make the espresso, the hot water is applied to the coffee granules for a very short time, as compared to the much longer period of exposure time when the professional barista makes espresso. Furthermore, the artistry and professional skill and experience of the barista is not available when using a coffee capsule.
A further technical problem with making espresso using a coffee capsule is ensuring that the coffee capsule that fits into the group head does not leak water and that the capsule does not get stuck in the group head. If the capsule does leak water, less coffee comes out of the brewing process and into the espresso. Furthermore, control is then lost over the exact percentage of water that should be present as an ingredient of the espresso and the optimal extraction rate cannot be achieved.
A further problem of making espresso using a coffee capsule is that a large manufacturer of coffee-making machines for espresso may have multiple types of group heads for their espresso making machines. For example, Societe Des Produits Nestle S.A. has several different group heads each having different structural characteristics and/or dimensions. Certain large manufacturers of coffee making machines deliberately make it difficult for coffee capsules not made by or for that manufacturer to be usable, for example so as to seal effectively, in the group heads of their machines. Furthermore, these manufacturers may it exceedingly difficult to create a coffee capsule that works in more than one of their group heads, and certainly not in all of them. This makes it impossible for a coffee capsule usable in one type of group head for one espresso making machine to be also usable in the group head of the other machines. Having to create separate coffee capsules for separate group heads significantly increases the manufacturer costs of espresso making.
Another technical problem is that the blades of the group head puncture the top of the coffee capsule. If the top of the coffee capsule is too soft, the puncture will not be easy and simple whereas if the coffee capsule is made from material that is too hard, it will be that much more difficult to achieve an effective seal against water leakage.
There is therefore a compelling need to have a method and/or apparatus for making espresso utilizing a coffee capsule (and hence enjoying all the advantages associated with the use of coffee capsules such as those mentioned above) without suffering from the drawbacks associated with making espresso using coffee capsules, such as the above-mentioned drawbacks and to thereby create espresso of the quality produced by professional baristas.